1. Field of the Invention
This invention relates to a method of manufacturing printed boards.
2. Description of the Prior Art
A conventional method of manufacturing printed boards comprises attaching a dry film to a printed board, cutting away any dry film portion projecting from the board manually or otherwise, exposing the dry film through a pattern mask, removing a protective film from the dry film, and developing the dry film. This method is, however, very inefficient, and requires a lot of time, since the step of cutting away the dry film portion projecting from the board interrupts the operation of a manufacturing line. A more serious problem which the conventional method involves is due to the possibility that fine chips of the dry film, dust produced when the edges of the board are ground, etc. may adhere to the dry film. These chips and dust are likely to shield light from a pattern on the printed board during exposure, since the pattern, such as of an integrated circuit, is extremely small.
The dry film is composed of a protective film and a photosensitive layer. The protective film is removed after the dry film has been attached to the printed board, and exposed to light. The removal of the protective film from each of a lot of boards is a highly time-consuming job.